feat(briefing): multi-article topic discussion endpoint for deep thematic analysis

src/fabledassistant/routes/briefing.py

@@ -544,3 +544,106 @@ async def discuss_article(item_id: int):
     ))
 
     return jsonify({"assistant_message_id": assistant_msg.id, "status": "generating"}), 202
+
+
+@briefing_bp.route("/topics/<topic>/discuss", methods=["POST"])
+@_REQUIRE
+async def discuss_topic(topic: str):
+    """Discuss all recent articles in a topic cluster — multi-article deep analysis."""
+    data = await request.get_json() or {}
+    conv_id = data.get("conv_id")
+    if not conv_id:
+        return jsonify({"error": "conv_id required"}), 400
+
+    uid = g.user.id
+
+    # Verify conversation belongs to user
+    conv = await get_conversation(uid, conv_id)
+    if conv is None:
+        return jsonify({"error": "Conversation not found"}), 404
+
+    if get_buffer(conv_id) is not None:
+        return jsonify({"error": "Generation already in progress"}), 409
+
+    # Find recent articles with this topic (last 2 days)
+    async with async_session() as session:
+        result = await session.execute(
+            select(RssItem)
+            .join(RssFeed, RssFeed.id == RssItem.feed_id)
+            .where(RssFeed.user_id == uid)
+            .where(RssItem.topics.contains([topic]))
+            .order_by(RssItem.published_at.desc().nullslast())
+            .limit(5)
+        )
+        items = list(result.scalars().all())
+
+    if not items:
+        return jsonify({"error": f"No articles found for topic '{topic}'"}), 404
+
+    # Fetch full content for each article
+    from fabledassistant.services.rss import _fetch_full_article
+
+    synthetic_tool_calls = []
+    for item in items:
+        content = await _fetch_full_article(item.url) if item.url else None
+        content = content or item.content or ""
+        synthetic_tool_calls.append({
+            "function": "read_article",
+            "arguments": {"url": item.url or ""},
+            "result": {
+                "success": True,
+                "type": "article_content",
+                "url": item.url or "",
+                "title": item.title or "",
+                "source": "",
+                "content": content[:8000],  # cap per article to stay within context
+                "truncated": len(content) > 8000,
+            },
+        })
+
+    await add_message(conv_id, "assistant", "", status="complete", tool_calls=synthetic_tool_calls)
+
+    user_prompt = (
+        f"I'd like to discuss the {len(items)} articles about '{topic}'. "
+        "Don't just summarize each one — draw connections between the sources, "
+        "highlight where they agree or disagree, and share your analysis of what "
+        "this means. Let's have a real discussion about this topic."
+    )
+    await add_message(conv_id, "user", user_prompt)
+
+    conv = await get_conversation(uid, conv_id)
+    assert conv is not None
+
+    history = []
+    for msg in conv.messages:
+        if msg.role == "system":
+            continue
+        msg_dict = {"role": msg.role, "content": msg.content or ""}
+        if msg.tool_calls:
+            msg_dict["tool_calls"] = [
+                {"function": {"name": tc["function"], "arguments": tc["arguments"]}}
+                for tc in msg.tool_calls
+            ]
+            history.append(msg_dict)
+            for tc in msg.tool_calls:
+                history.append({"role": "tool", "content": json.dumps(tc.get("result", {}))})
+        else:
+            history.append(msg_dict)
+
+    model = await get_setting(uid, "default_model", "") or ""
+
+    assistant_msg = await add_message(conv_id, "assistant", "", status="generating")
+    buf = create_buffer(conv_id, assistant_msg.id)
+
+    asyncio.create_task(run_generation(
+        buf, history, model,
+        uid, conv_id, conv.title or "",
+        user_prompt,
+        think=True,
+    ))
+
+    return jsonify({
+        "assistant_message_id": assistant_msg.id,
+        "status": "generating",
+        "article_count": len(items),
+    }), 202